Current networks typically include devices, such as routers, switches or gateways, which transfer or switch data from one or more sources to one or more destinations. A packet is one format of data in which encapsulated data can be transmitted through a network. A router is a switching device that receives packets containing a data payload and control information at input ports and, based on destination or other information included in the packets, may forward the packets through output ports to the destinations or intermediary destinations. Routers determine the proper output port for a particular packet by evaluating header information included in the packet.
Existing routers include forwarding engines for receiving and forwarding incoming packets to their intended destinations. To forward incoming packets from input port to an appropriate output port, routers may perform complex data manipulation actions. Such data manipulation actions may include storing and retrieving encapsulation data required for constructing outgoing packet headers and forwarding outgoing packets based on routing data accumulated using network routing protocols.
In network devices, such as, for example, routers, switches or integrated security service gateway systems, packets travel through multiple line cards (e.g., security service cards or input/output (I/O) line cards) while being processed during the packet forwarding process. Ingress I/O cards of the multiple line cards are typically the first service cards in the network device and egress I/O cards of the multiple line cards are typically the last service cards in the network device.